Your Comprehensive Guide to Cultivating Avocado Trees

Start by poking toothpicks around the avocado seed, pushing them in about a half-inch. Suspend the seed over a small glass filled with water so the bottom inch of the seed is in the water. Change the water every five days or so to keep it fresh. Roots will appear after about three weeks, and eight weeks after that, a small seedling will start poking out of the top.

When the seedling reaches six inches, cut the stem in half to encourage new growth. When it has few adult leaves and robust roots, transfer it to a 10-inch wide pot with drainage holes. Use general potting soil, or add sand to encourage appropriate moisture levels.

When grown outdoors, an avocado tree can reach as high as 60 feet. When kept as a houseplant, you can trim it to stay much smaller. Avocado trees require frequent and significant pruning to get a bushy look. Every time it hits a six-inch growth milestone — at 12 inches, then again at 18 inches — cut off the top two sets of leaves. As the plant grows larger, transplant it into larger pots, but only go up two inches in diameter each time.

Avocado trees thrive with full sun exposure, but they don't like cold weather. Keep the plant in a sunny window when the temperature is 45 degrees or less. When the weather gets warmer and the tree has matured a bit, take the pot outside to get more sun. Keep younger plants in partial shade outside, though, as the harsh sunlight can burn the newly established leaves.

For best results, avocado trees need between four and six hours of direct afternoon sun every day.

Avocados like moist soil, but overwatering can lead to root rot. Wait until the top inch of the soil is dry, then water thoroughly until the water runs out of the drainage holes on the bottom of the pot. If you're keeping your potted avocado plant outside in hot, dry weather, check the soil more frequently and water as needed.

Lace bugs, mites, and caterpillars can all attack avocado trees. Lace bugs cause the leaves to yellow, dry, and eventually fall off; while mites can cause the leaves to turn a bronze color. Caterpillars attack the leaves, flowers, and fruit and do a lot of damage in a short period.

Borers can be an issue with more mature trees, as they eat through the bark. Thrips are another pest to look out for. Although they don't cause much damage to the tree itself, they can drastically affect the health and production of fruit.

The most serious disease for avocado trees is avocado black streak, which starts by causing yellow leaves and poor fruiting and causes cankers and death in time if untreated. Avocado trees are susceptible to fungal infections — Phytophthora canker affects the lower trunk, causing dark fluid-filled sores, while Dothiorella causes white, powdery areas on the trunk and branches.

Verticillium can cause the leaves on one side of the tree to wilt and fall off.

In the summer, feed your plant with a fertilizer that contains adequate nitrogen and a small amount of zinc. You can only plant avocados outdoors in certain climates: they thrive in temperatures between 60 and 85 degrees F and need at least eight hours of sunlight every day.

When your avocado tree is established, you can use an air-laying method to propagate it. Scar a branch by cutting into it with a clean blade, then wrap the area in rooting hormone. Eventually, roots will form while the branch is still on the tree. Wait until the roots are more robust, then cut off the entire branch and plant it in the soil.

Avocado trees take anywhere from five to ten years or more to produce fruit, so the first step to harvesting avocado is to be patient. If and when you do get fruit, remember that avocados do not ripen on the tree. After they reach a decent size, harvest them, then wait a few days before eating them. If you're unsure if the fruit is ready, choose the largest avocado on the tree with dry skin and let it ripen for a few days. If it shrivels up at the stem or stays rubbery, you picked it too early. Wait a month and try again. If it's too soft when you cut into it, you're too late. Next year, harvest a few months earlier.

Avocados are incredibly nutritious and easy to prepare. Cut them and add them to the top of whole-grain toast or get creative and make homemade guacamole. Avocados contain more potassium than bananas and are loaded with heart-healthy fats and fiber. Eating avocados can help lower bad cholesterol and increase good cholesterol and contain antioxidants that support the immune system.